Conventionally, during a sewing operation, so called fastening stitches have been formed at the beginning and the end of pattern sewing sequence in order to prevent disintegration of seams formed on a workpiece cloth. The fastening stitches are formed in a predetermined stitch-pitch of approximately 0.2 mm, for a predetermined number of stitches of 3 or 4 stitches, for example.
One of such examples is given in JP H03-139388 A which discloses a data processor for an embroidery sewing machine including sewing data memory for storing enclosed area sewing data and a data-end detector that detects a starting end and a terminating end of the enclosed area sewing data stored in the sewing data memory.
The data processor stores fastening stitching data in a memory area immediately preceding the starting end of the enclosed area sewing data, and immediately following the terminating end of the enclosed area sewing data. During a normal sewing operation, by controlling the embroidery sewing machine based on the enclosed area sewing data and fastening stitching data, fastening stitches are formed at the starting end and the terminating end of the enclosed area of the embroidery pattern.
Household sewing machines conventionally allow execution of a normal sewing operation and a free motion sewing operation. Normal sewing operation is carried out by feeding a workpiece cloth by a feed dog which is moved above and below the upper surface of a needle plate provided on a sewing machine bed. Free motion sewing operation, on the other hand, allows the user to manually feed the workpiece cloth freely while preventing the feed dog to protrude above the upper surface of the needle plate. When executing the free motion sewing operation, a presser foot dedicated for free motion sewing operation is attached to a presser bar and the workpiece cloth placed on the upper surface of the sewing machine bed is manually moved along guidance provided by indicators as a baseline drawn prior to the sewing operation.
In free motion sewing operation where workpiece cloth is moved manually, fastening stitches also need to be formed manually. However, in order to form fastening stitches in a small stitch-pitch, the workpiece cloth needs to be moved little by little, which requires considerable technical maturity on the part of the user. Such being the case, it has been a difficult task for inexperienced users to form fastening stitches during a free motion sewing operation.